A few years ago there were a number of automotive manufacturers putting serious money into hydrogen fuel-cell vehicles. These vehicles promised to have a driving range similar to a conventional gasoline-powered automobile, but produce no emissions to pollute the atmosphere.

However, the vehicles faced several daunting challenges, including the lack of a hydrogen fuel infrastructure and the fact that hydrogen is highly flammable and difficult to store.

Volkswagen CEO Martin Winterkorn stated this week that hydrogen fuel cells have failed to live up to promises and are unlikely to become an efficient and cost-effective way to power cars in the near future.

Winterkorn said, "I do not see the infrastructure for fuel cell vehicles, and I do not see how hydrogen can be produced on large scale at reasonable cost. I do not currently see a situation where we can offer fuel cell vehicles at a reasonable cost that consumers would also be willing to pay."

While Volkswagen doesn't see a near-term future with hydrogen vehicles, other manufacturers continue to move forward with the technology. Mercedes-Benz reached a deal with Ford and Nissan-Renault with a goal of selling the first production fuel-cell vehicle starting in 2017.

Back in 2010, a study was published predicting 670,000 fuel cell powered vehicles would be sold annually within a decade. So far, that prediction doesn't seem likely to come true.

Comparatively speaking, not really. Gasoline vapor is quite flamable, but the liquid itself is not easily flamable (to get an explosion with a gasoline tank you would need to heat the tank until the liquid was hot enough to quickly become a vapor, then ignite it - which is why cars don't explode when you rupture a fuel tank)

Look at it this way, at room temperature open a barrel of gasoline and throw a match on it and it will burn - do the same to a barrel of hydrogen and it will explode...

Actually, it probably wouldn't. Hydrogen being lighter than air would tend to leave the open barrel rapidly while gasoline vapors, being heavier than air, will linger. A leaky gas tank is a much larger fire danger than a leaky hydrogen tank. The biggest problem is that to store enough hydrogen to fuel a vehicle you need to use compressed gas cylinders or some other expensive or unproven method.

Perhaps you should read what I said. I did not say, leave it open and throw a match on it some time later. Nor was I referring to a leaky tank.

If you open a gas barrel and immediately throw a match on it it will burn but be extremely unlikely to explode. Do the same with an equivalent hydrogen barrel and the only way it is likely not to explode is if the rush of hydrogen coming out blows out the match before it can ignite the hydrogen.

So as I said, comparatively speaking, gasoline is not highly flamable when compared to hydrogen.

quote: Actually, it probably wouldn't. Hydrogen being lighter than air would tend to leave the open barrel rapidly while gasoline vapors, being heavier than air, will linger. A leaky gas tank is a much larger fire danger than a leaky hydrogen tank. The biggest problem is that to store enough hydrogen to fuel a vehicle you need to use compressed gas cylinders or some other expensive or unproven method.

Hydrogen, with current technology, needs to be a pressurized gas. This is a problem, not just because of issues arising from rapid depressurization of the fuel tank, but also the volatility of the gas itself.

When was the last time hydrogen reacted with open air? You get the Hindenberg disaster. In a car, the best case scenario is the fuel tank stays relatively intact ... and that very rarely happens. A single leak from a gasoline-powered car isn't enough to destroy it and kill everyone onboard, as you also need an electrical spark or fire elsewhere. A single leak from a pressurized hydrogen gas tank gives you an explosion, destroying the entire car and killing everyone onboard.

This is why propane has a pungent smell added to the mixture - if you can smell it, get out of whatever you're in before you die to the leak going ablaze. Hydrogen as a fuel is more dangerous than THAT.

quote: Look at it this way, at room temperature open a barrel of gasoline and throw a match on it and it will burn - do the same to a barrel of hydrogen and it will explode...

Fun fact: It's possible to flick a lit cigarette into a container of gasoline fast enough that it will put out the cigarette without the gas burning or exploding. I don't really want to know how this was first discovered and I'd rather not be around to see anyone try it.